How do you say "warm reminder" in English?

The English word for warm reminder is kindly reminder.

Explanation of key vocabulary

reminder　

English [r?'ma?nd?(r)]? American [r?'ma?nd?r]

n. Reminder; prompt; reminder

These ruins are an eloquent reminder of the horrors of war.

These ruins vividly remind people not to forget The horrors of war.

Synonyms

notice

English ['n?t?s] American ['no?t?s]

vt. Notice; note; notice

n. Notice; notice; notice

He walked so fast that he didn't notice his wife.

He walked so fast that he didn't notice his wife.

He walked so fast that he didn't notice his wife. It was so fast that even his wife didn't notice.